Outfit for alternating-current vapor-lamps.



P. H. THOMAS.

OUTFIT FOR ALTERNATING CURRENT VAPOR LAMPS. APPLICATION FILED SEPT. 27, 1905 1,079,379, Patented Nov. 25, 1913.

j] F5004 1 4 rave y Z2 4 Snow vim I To all whom it may concern:

UNITED STATES. PATENT. OFFICE.

PERCY H. THOMAS, OF MONTCLAIR, NEW JERSEY, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO COOPER HEWITT ELECTRIC COMPANY, OF HOBOKEN, NEW JERSEY, A

CORPORATION OF NEW JERSEY.

OUTFIT FOR ALTERNATING-CURRENT VAPOR-LAMPS.

Specification 0! LettersPatent.

Application filed September 27,4905. Serial N 0.- 250,255.

Be it known that I, PERCY H. THOMAS, a citizen of the United States, and resident of Montclair, county of Essex, State of New Jersey, have invented certain new and useful Improvements in Outfits for Alternating-Current Vapor-Lamps, of which the following is a Specification.

' In supplying customers With outfits which include alternating current vapor lamps, it

is found that there' is. difiiculty in securing anything like uniformity in the outfit required -for circuits carrying different voltages and for meeting different conditions in the lamp circuit itself. At the same time, it tends to economy of manufacture to standardize the outfit as much as possible and to satisfy the various conditions of actual service. It would, for example, bea substantial improvement in the art to provide means whereby a standard outfit could be supplied for voltages ranging from 240 down to 100 volts without modifying the size of the voltage absorbing ballast employed "as a means of regulation and withoutchang 1 ing substantially the size of the auto-transformer which maybe introduced between the supply circuit and the" lamp circuit. When a ceiling outfitis employed, that is, an inclosing case located neara ceiling which may be of combustible material, this uniformity in the .size and general style of theapparatus is particularly desirable, if

only effective means are provided forreducing the energy losses in the auto-transformer.

It is the object of-the presentinvention to provide means whereby all the desirable features mentioned above may be combined and the desired results successfully obtained.

The attempt hasalready been made to accomplish some of the objects above mentioned bylocating the above mentioned ballast or other regulatingdevice on the line "side of the auto-transformer; but it is found that such an arrangement is not adequate to accomplish all the results aimed at herein and this invention is intended to remedy the defects of prior systems of distribution rel-ating to alternating current vapor lamps in the particulars pointed out in this specification. In some instances it may be desirable to operate a number of lamps from the same auto-transformer, each with its own ballast;

but this cannot be accomplished byplacing -In' carrying out the present invention I locate the :ballast or other regulating device :in the lead of one or more of the positive "electrodes "of 'the alternating current lamp eral alternations between the negative electrode and the positive electrodes in such a manner that equal quantities of energy will be absorbed by the energy storing or maintaining coil which always forms a part of the apparatuses is noW wellimown. In

"other words, the voltage applied between-the 'negative electrode and everypositive electrode in whose lead a ballast is included is enough higher than the voltage applied be tweenthe negative electrode and any-other positive electrode orelectrodes -'-to compensate for the additional resistance of the ballast. Furthermore, to secure the minimum size of auto-transformer, when the supply voltage is normallyless than that which-is necessary between the positive electrodes, thesupply -is applied to such aportion'of the auto-transformer as to allow thee'nerg'y to pass substantially directly line" to damp when traversing theballast.

By virtue of the'describedarrangement,

1 Patented Nov.-25, 1913.

.the ballast on the line'side of the transformer.

the ballast servesto limit-the' amount-of current flowing'throu'gh the lamp at any instant,--as at starting, whemconditions are favorable for establishinga short-circuit between positive electrodes.

invention will be understood by reference to the-accompanying drawings-1 in which- Figures 1 and 2 a're diagrammatic views 7 of circuits suitable for carrying out -myiim -vention In Fig. 1, 1 is an auto-transformer'supplied from mains, 2 and 3. The lamp to be operated is shown at Land -the .sa-me is-sup- -pl1ed with positive electrodes, 5 'and'G, and

with a negative electrode, 7. The connecformer 1 and the negative electrode 7 is contime to the positive electrodes extend from the respective terminals of the auto-trans nected through a choke-coil 8, to an intermediate point, 9, of the transformer. .The line ate point, of a current re wire 2 is also connected to"an intermediate point, 10, of the transformer. Inthe lead to the positive electrode 5 a ballast, 11, such as is frequently used for controlling vary- 1 ing voltages and vapor pressure variations in direct current lamps of this character, is-

introduced, the lead to the other positive electrode being generally unimpeded. One

suitable form of such ballast consists of an iron wire placed in hydrogen as and operated at 'or near red heat. T e particular form of the ballast utilized, is, however, not a part of the present. invention. It will be seen'that voltage-applied to the circuit including the ballast llis reater than that applied to the unimpeded circuit. By a 'proper adjustment of the connections to the auto-transformer,this distortion of the balance between the two sides of the circuit -may be made to aflectequally the maintaining or sustaining coil 8 so that in operation the unbalancing of the applied electro-motive-forces will result in a uniform action upon the two circuits, resulting in a steady operation of the lamp 4.

In Fig. 2 I illustrate a somewhat difierent mode of unbalancing the circuits, the main difference being that the' line conductors 2 and 3 are connected to the terminals of the auto-transformer and the adjustment made by the connections on the lamp side of-the circuit, This arrangement is particularly suited to cases wherethe line supply is naturally greater than the voltage to e de 'livered to the lamp.

The principles of the invention herein disclosedare obviousl applicable" not only to'singlephase but po yphase lamps as well. I

1. The comblnation with'a single phase alternating current source, a vacuumdevice comprisin electrodes and a va orizable reconstructing cathode therein an an alternating current transformer winding for supplying said device, connections from the ne ative electrode to an intermediate ointot t e winding and from the positive e ectrodes to points on the winding on opposite sides of said intermedilating device in the lead to one positive e ectrode, the relati've position of, the points of connection in th .winding being suchas'to cause avolftage to e impressed upon thepositive electro e whose'lead contains the said regulating dea hermetically sealed and. .completely ex austed container, positive ings, of connections for supplying current through said device from both Waves of the supply and means for deriving from said supply unequal voltages whereby unequal currents tend to flow from alternate waves of the source and an inductance in the circult of the rectified current to steady' and equalize the current flow produced by said unequal voltages. 1

3. The combination With an apparatus adapted to utilize separately both "waves of an alternating current supply, an autotransformer connected with said supply and a controlling device traversed by current derived from one wave of said'supply, of

means for passing energy through said autotransformer with a small ratio of transformation from said supply to said apparatus through said controlling device and means for passing energy with a larger ratio of transformation from the other wave of the supply in the original direction through said apparatus, thus reducing the transformation losses of the energy supplied through said controlling device. a

4. In a system of electrical distribution wherein an alternating current vapor lamp is supplied from a single-phase source, av

transformer, connections from the transformer to one of the positive electrodes of the lamp through a current regulating device, connections'from another portion of the transformer to the other positive electrade and means whereby the transformer is unbalanced, so that the voltage supplied through the positive electrode connected with said regulating device shall be enough higherthan the voltage applied to the other positive electrode to compensate for th'e re sistance' of the said device.

Signed at New .York, in the county of New York, and State of New' York, this 25th day'of September A. D. 1905 PERCY H. THOMAS.

Witnesses WM. H. GAPEL', I Tnos. H BnowN. 

